Development of a dual-pump coherent anti-Stokes Raman spectroscopy system for measurements in supersonic combustion

Magnotti, Gaetano; Cutler, Andrew D.; Danehy, Paul M.

doi:10.1364/ao.52.004779

Cited by 20 publications

(10 citation statements)

References 44 publications

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“…Danehy et al carried out a number of studies in which CARS was applied to supersonic flows. [143][144][145] Clauss and collaborators applied hydrogen CARS thermometry to combustion systems of relevance to rocket engines. For example, they studied cryogenic liquid oxygen (LOX) and gaseous oxygen-fed hydrogen [146][147][148] and hydrocarbon 147,149,150 flames operated under rather extreme conditions, i.e., pressures as high as 20 MPa and temperatures as high as 3000 K. Similar temperatures were measured in the jet flame of a staged oxy-fuel burner of a large-scale industrial furnace fueled with natural gas.…”

Section: Coherent Anti-stokes Raman Scatteringmentioning

confidence: 99%

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

Ehn

Zhu

et al. 2017

Appl Spectrosc

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Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities. The aim of this article is to present selected important laser-based techniques for gas-phase diagnostics focusing on their applications in combustion and aerospace engineering. Applicable laser-based techniques for investigations of turbulent flows and combustion such as planar laser-induced fluorescence, Raman and Rayleigh scattering, coherent anti-Stokes Raman scattering, laser-induced grating scattering, particle image velocimetry, laser Doppler anemometry, and tomographic imaging are reviewed and described with some background physics. In addition, demands on instrumentation are further discussed to give insight in the possibilities that are offered by laser flow diagnostics.

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Section: Coherent Anti-stokes Raman Scatteringmentioning

confidence: 99%

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

Ehn

Zhu

et al. 2017

Appl Spectrosc

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“…This was attributed to inaccurate modeling of Raman linewidths for higher-J Q branch rotational lines. Magnotti et al [26] probed N 2 , O 2 , and H 2 in a supersonic combustion system. Good agreement between measured O 2 concentration and theory was shown in their calibration measurements on a Hencken burner.…”

Section: Introductionmentioning

confidence: 99%

Dual-pump vibrational CARS measurements of temperature and species concentrations in turbulent premixed flames with CO2 addition

Han

Satija

Kim

et al. 2017

Combustion and Flame

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a b s t r a c tA dual-pump vibrational coherent anti-Stokes Raman scattering (DPVCARS) system was applied for simultaneous temperature and species concentration measurements in jet flames on a newly developed piloted axisymmetric reactor assisted turbulent (PARAT) premixed flame burner. Turbulent lean premixed methane/air round jet flames with varying CO 2 dilution were stabilized using an annular flow of hydrogen at the flame base. Carbon dioxide was injected into the fuel stream to simulate effects of dry exhaust gas recirculation (EGR). The flames were operated at a nearly constant Reynolds number, Lewis number, and adiabatic flame temperature to minimize thermal and transport effects. Velocity boundary conditions at the burner exit were measured using particle image velocimetry. Simultaneous temperature and major species concentrations (O 2 and CO 2 ) were measured along the axial direction at the burner centerline and along the radial direction at representative axial locations above the burner. Progress variables calculated based on the temperatures were used to study the mean flame brush thickness and the turbulent burning velocity. Probability density functions (PDFs) of temperature at various locations are presented and discussed. The DPVCARS measurements provide an experimental database including temperature and turbulent burning velocity for combustion model evaluation and validation and demonstrated a strong potential for flame structure investigation with future improvement on spatial resolution and signal to noise ratio. The merits and limitations of vibrational CARS for diagnostics in turbulent premixed combustion are discussed. The results show that flames with CO 2 addition depart from the universal mean flame brush structure, while their RMS fluctuation values at an identical mean temperature collapse with the undiluted flame. The CO 2 addition increases the combustion intensity with a decrease in turbulent burning velocity when minimizing the thermal and transport effects.

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“…O'Byrne et al [6] have performed extensive coherent anti-Stokes Raman scattering (CARS) measurements of temperature and O 2 , N 2 , and H 2 mole fractions in a model scramjet combustor fueled with H 2 . [7][8][9]. Additionally, Fulton et al [10] compared LES/RANS simulations to CARS measurements of temperature, and O 2 , N 2 , and H 2 concentrations in supersonic combustion behind a step.…”

mentioning

confidence: 99%

Raman scattering measurements of mixing and finite-rate chemistry in a supersonic reacting flow over a piloted, ramped cavity

Grady

Pitz

Carter

et al. 2016

Combustion and Flame

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UV Raman scattering is applied to measure fuel/air mixing and combustion of a Mach-2 air stream flowing over a step-ramp cavity fueled with 70% methane/30% hydrogen. Average and RMS fluctuations of temperature and major species profiles as well as scatter plots of simultaneous temperature and chemical scalars are determined from single-shot Raman scattering measurements along a 6-mm line transverse to the main supersonic flow. In the fuel-rich regions of the pilot cavity, the 248-nm KrF laser induces broadband fluorescence interference that reduces the number of analyzable Raman spectra; nonetheless, on the whole, a significant fraction of the spectra were reducible. In the cavity, hydrogen fuel reacts quickly resulting in a uniform water concentration in the recirculation zone. Methane reacts slowly to carbon monoxide/carbon dioxide in the cavity, leading to non-uniform concentrations of these species. Mean and instantaneous mixture fraction data inside the shear layer were indicative of oxygen transport across the shear layer. Temperature, water, and oxygen fluctuations are fairly constant throughout the combustor due to recirculation/turbulent transport across the shear layer and the slow reaction of methane.

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Development of a dual-pump coherent anti-Stokes Raman spectroscopy system for measurements in supersonic combustion

Cited by 20 publications

References 44 publications

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

Dual-pump vibrational CARS measurements of temperature and species concentrations in turbulent premixed flames with CO2 addition

Raman scattering measurements of mixing and finite-rate chemistry in a supersonic reacting flow over a piloted, ramped cavity

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